During an impressive 35 hour stretch over the weekend, over 100 developers came together in San Francisco to hack the electronic signature using the DocuSign Enterprise API and other APIs along the way. The winners show the breadth of applications built on DocuSign's platform, taking e-signatures beyond the legal document.

Zillow has released an application for iPhone users that builds on their Zillow API, the Microsoft Virtual Earth API and the iPhone's GPS capabilities. The Zillow iPhone app detects your location and shows data about nearby homes, including market values, photos, and which ones are for sale. It's a great example of a mobile mashup application that uses multiple APIs in meaningful location-aware context.

Potentially no industry was impacted as much as real estate by mapping APIs. Over five years later, it takes more than pins on a slippy map to create a useful real estate mashup. The three below are worth noting because each uses a different platform: web, WordPress and Android. Of course, we know our directory of 229 real estate mashups doesn't cover everything. Get the word out and add a mashup.

This API endpoint implements RESO's Web API and provides data using the RESO Data Dictionary version 1.1. Flexmls® IDX products enable Agents to display listings of other brokers in the MLS on their...